Canister light battery

[tomfcrist]

I was given an older dive rite wreck can light with an MR-11 light head on it, but the battery is lead acid 12v 2.9ah...and it's dead.
Assuming it would fit in the canister would there be any problems with putting say a 12v 10ah nimh battery in as a replacement?

 

[cool_hardware52]

I was given an older dive rite wreck can light with an MR-11 light head on it, but the battery is lead acid 12v 2.9ah...and it's dead.
Assuming it would fit in the canister would there be any problems with putting say a 12v 10ah nimh battery in as a replacement?

From an electrical stand point increasing the capacity (amp hours) will only increase the run time. 10 Nimh cells will yield a nominal 12 volt pack. Some the earlier Solarc ballasts were quite particular to input voltage however. At full charge 10 Nimh cells can be at about 14.5 volts. A fully charged sla would be 6 x 2.3 = ~13.8 Your ballast might not tolerate the extra 0.8 volts. One solution is a simple three terminal voltage regulator to drop the voltage, or even simpler a couple 1N4001 diodes in series between the battery and ballast, but not between the battery and charger.

Tobin

 

[tomfcrist]

You the man Tobin. Would it be unwise to give it a shot without the regulator or diodes? Worst case scenario is toasting the ballast right?

 

[cool_hardware52]

You the man Tobin. Would it be unwise to give it a shot without the regulator or diodes? Worst case scenario is toasting the ballast right?

Yup, you might let the smoke out of the ballast. The bad news is IIRC those ballasts are out of manufacture.

Tobin

 

[lucca brassi]

NITERIDER HID REPLACEMENT LIGHT BALLAST, UNIVERSAL DUAL WATT TYPE | eBay

 

[cool_hardware52]

NITERIDER HID REPLACEMENT LIGHT BALLAST, UNIVERSAL DUAL WATT TYPE | eBay

That would be the hot ticket. I'd still start with a couple diodes in series with the original ballast.

Tobin

 

[tbone1004]

personally I'd stay away from NiMH and just go straight to a 14.8V lipo, the ballast should be able to handle that with no issue and you'll get much more burn time. Alternative would be 12.8v LiFe.

 

[nimoh]

personally I'd stay away from NiMH and just go straight to a 14.8V lipo, the ballast should be able to handle that with no issue and you'll get much more burn time. Alternative would be 12.8v LiFe.

I'm by no means a battery expert, but isn't it significantly more complicated to make a lithium battery due to the electronics and matching up a charger for a particular pack?

I briefly looked into making a lithium pack for something and quickly realized it was way over my head

 

[tbone1004]

making one yes, buying one no. You can grab them from Battery space pretty easily. I don't know the dimensions of the wreck canister, but they have lots of premade packs and you should be able to find one that will fit. Strip the ends of the leads from the pack, put on whatever connector is on the lid, and good to go.